Sonic delay line device

ABSTRACT

A multifaced rod of acoustical transmitting material, for use with an object identifying apparatus, has attached to one of its ends a piezoelectric element. Preselected faces of the rod are at spaced intervals, slotted, or notched, perpendicular to the axis of the rod and to the face in which they are cut. An acoustical wave produced by the piezoelectric element in response to an electrical signal is reflected by each of the notches in turn. The resulting echoes are received by the piezoelectric element which in response thereto produces a coded representation of the identity of the object to be identified.

United States Patent [72] Inventor [21 1 Appl. N o. [22] Filed [45]Patented [73] Assignee [54] SONIC DELAY LINE DEVICE 5 Claims, 2 DrawingFigs. [52] US. Cl 333/30, 328/56, 340/347, 340/313, 340/348, 179/18 [51]Int. Cl. H03h 9/30, H03k 13/00 [50] Field ofSearch 333/29;

340/173 (MS), 174 (MS), 167 (B), 191, 345, 404, 347, (inquired); 328/56(lnquired); BIO/8.1, 8.3; 307/106; 333/30; 179/100.2 (CH), 100.4 (MS),84

[56] References Cited UNITED STATES PATENTS 2,907,958 10/ 1959 Skaggs3,020,496 2/1962 Feuerstein et al. 333/30 3,025,479 3/1962 333/303,264,583 8/1966 333/30 3,277,404 10/1966 Fabian 333/30 PrimaryExaminerl-lerman Karl Saalbach Assistant Examiner-Paul L. GenslerAttorneys-John B. Sponsler, Gerald R. Woods, James C.

Davis, Jr., Frank L. Neuhauser, Oscar B. Waddell, Melvin M. Goldenbergand Arnold E. Renner ABSTRACT: A multifaced rod of acousticaltransmitting material, for use with an object identifying apparatus, hasattached to one of its ends a piezoelectric element. Preselected facesof the rod are at spaced intervals, slotted, or notched, perpendicularto the axis of the rod and to the face in which they are cut. Anacoustical wave produced by the piezoelectric element in response to anelectrical signal is reflected by each of, the notches in turn. Theresulting echoes are received by the piezoelectric element which inresponse thereto produces a coded representation of the identity of theobject to be identified.

' PATENTEDI-IAR 2km 3568104 INVENTOR.

ILEY

SONIC DELAY LINE DEVICE BACKGROUND OF THE INVENTION In theidentification of objects one type of apparatus utilizes a piezoelectricelement to produce anacoustical wave in a delay line or the like towhich it is attached. The acoustical wave propagates through the delayline and is reflected from fixed deformities in the line.The'deformities are at predetermined spaced linear intervals in the lineso that the acoustical wave is reflected by the deformities in the orderin which the deformities occur. Depending on the combination of theplacement of the deformities a code is formed which representative ofthe identity of that particular delay line, or the object to which it isattached. r a

At times it may be necessary to change the indentity of the object, orto identify new objects, in which case a change in the obstructions isrequired. In some of the identification apparatus the delay line needsto be entirely replaced by a delay line which is coded in themanufacturing plant. Other types utilize clamps which are attached atmeasured increments whereby an echo is provided. These special clampsmust therefore be stocked. Some other types of identification apparatusdepend on the frequency of the piezoelectric element to identify'theobject. Receding of-this type requires replacement of the piezoelectricelement or the entire identification apparatus. In either of theexamples it is necessary that a stock of replacement units is on handfor the purpose of coding and recoding of the various objects to beidentified.

SUMMARY OF THE INVENTION nEscRmTroN OF THE DRAWINGS 'FIG.'1 shows 'areflection apparatus for the purpose of explanation of the principle.

FIG. 2 shows an acoustical rod coded for use in an identificationapparatus. I

DETAILED DESCRIPTION Referring to FIG. I wherein a piezoelectrictransponder 13 is rigidly attached to the base 14 of a rod or column 15made of an acoustically conductive material, such as metal or plastic,which has a series of reductions 17-20 along the axis perpendicular tothe base 14. The reductions are on opposite sides and cause aseries' ofsurfaces 27-30 to be formed which are parallel to base 14; i.e.,perpendicular to the axis of the rod 15. The end 31 opposite the base 14is perpendicular to the axis of the rod 15.

The transponder 13 is provided with two electrical connections 21 and 22which are normally connected to an altemating current supply source (notshown), whereby the transponder is intermittently caused to vibrate atthe frequency of the A.C. supply source (not shown). Due to the physicalarrangement between the transponder 13 and the base 14 of the rod 15,these vibrations are transferred to the rod 15 where they propagatethrough the material along the entire axis of the rod. Upon reaching theend 31 some of the vibrations are returned to their origin, transponder13(Similarly the perpe dicular surfaces 27-30 cause some of thevibrations to be reflected" to the transponder 13. The transpondersubjected to these acoustical vibrations produces electrical impulses inresponse thereto. The first resultant Impulse occurs when the firstacoustical wave reflected from the perpendicular surfaces 27 and 29reaches the transponder 13. A second impulse is produced by thereflected acoustical wave from the perpendicular surfaces 28 and 30, anda third impulse occurs when the reflected acoustical wave from endsurface 31 reaches the transducer. The elapsed time between the impulsesdepends on the distance between the transponder and the perpendicularsurfaces 27-31 and the acoustical properties of the material used. Theseproperties also determine the number of perpendicular surfaces andconsequently the number of impulses which may be expected to bereflected, due to the attenuation of the material which determines themaximum length of the bar 15. For example, a bar made of plastic havinga relatively high attenuation is limited to conditions where relativelyfew impulses are needed, while brass when used will allow a moreextensive number of reflections or echoes to be transmitted. Thetransducer 13 operatesas a transmitter first by producing an acousticalsignal, and then as a receiver for converting the acoustical echoes ofthat signal to a number of electrical impulses corresponding to thenumber of perpendicular surfaces 27-30 present in the rod I5. In FIG. 2an octagonal column or rod 41, having a base 59 to which a piezoelectrictransponder (not shown) is rigidly attached, has a second surface 61parallel thereto at the opposite end of the rod. The eight faces 63-70joining the base 59 and the end 61 are each provided with a slot ofwhich 43-46 are shown to be located in faces 63-66 respectively. Aspreviously pointed out, these slots may be fabricated 'upon the variousfaces according to a predetermined coding, or the slots may be manuallycut into the faces at appropriate locations when the device is receded,or replaced in the field. Perpendicular surfaces 53-56, which correspondto surfaces 27-30 in the column in FIG. 1, are formed by each of theslots 43-46, respectively. The echoes derived from the acoustical waveproduced by the piezoelectric transponder (not shown) which is reflectedfrom the perpendicular surfaces 53-46 are received by the transponderand converted to electrical signals thereby.

In practice some of the sides 63-70 arenot notched, so that under thoseconditions no echo is received by the transponder due to the absence ofvertical surfaces and no electrical signal is developed, resulting in a'code corresponding to the placement of notches appearing in theoctagonal bar 41.

3. The invention claimed in claim I wherein the sequential order of saidcoded output is proportional to the distance between said transducer andsaid deformities.

4. The invention claimed in claim 1 wherein said elongated member is ofpolygonal cross section, and said deformities are disposed alongselected sides of said member so that each one of a predetermined numberof said sides contains oneof said deformities.

5. The invention claimed in claim 4 wherein said deformities areindentations traversing the sides of said elongated member substantiallyperpendicularto the longitudinal axis.

1. A sonic coding apparatus comprising: a. a transducer for producing asonic impulse and for producing a signal in response to a reflectedimpulse; and b. an elongated member of sonic transmitting maTerialattached to said transducer, said member having a series of deformitiesspaced along the length thereof, said deformities serving to produce aseries of reflected impulses for actuating said transducer to produce acoded output corresponding to the number of deformities.
 2. Theinvention claimed in claim 1 wherein said transducer is a piezoelectriccrystal.
 3. The invention claimed in claim 1 wherein the sequentialorder of said coded output is proportional to the distance between saidtransducer and said deformities.
 4. The invention claimed in claim 1wherein said elongated member is of polygonal cross section, and saiddeformities are disposed along selected sides of said member so thateach one of a predetermined number of said sides contains one of saiddeformities.
 5. The invention claimed in claim 4 wherein saiddeformities are indentations traversing the sides of said elongatedmember substantially perpendicular to the longitudinal axis.